Proceedings of the National Academy of Sciences (2004) - Comment
pubmed: 15148378  doi: 10.1073/pnas.0402629101  issn: 0027-8424  issn: 1091-6490 

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Brian Zarnegar, Jeannie Q. He, Gagik Oganesyan, Alexander Hoffmann, David Baltimore, Genhong Cheng